1. Field of the Invention
The present invention relates to electron beam apparatus, including scanning electron microscopes and the like, and method of operating such apparatus.
2. Description of the Background Art
There is an increasing need for high-resolution scanning electron microscopes (SEMs) in all areas of development and manufacture of micro-electronic and opto-electronic components. High-resolution scanning electron microscopes are useful so as to visually evaluate sub-micrometer structures. High-resolution SEMs may be used to identify deviations from standard patterns and to acquire and evaluate topographical data such as heights, widths or angles of inclination.
Unfortunately, conventional, non-immersion, scanning electron microscopes do not have the required resolution of a few nanometers unless very high landing energies above about 10 kilo-electronVolts are used which may cause resist structures and, integrated circuits to be damaged and non-conductive or high resistant specimens to be disadvantageously charged.
It is highly desirable to improve electron beam apparatus, including scanning electron microscopes and the like, and methods of operating such apparatus.